The invention pertains to methods of forming integrated circuit packages, as well as to devices for separating integrated circuit packages.
Circuit constructions having integrated circuit (IC) chips bonded to circuit boards (such as SIMMs and DIMMs) can be fabricated by joining IC chips on a single large circuit board comprising a plurality of the constructions. The circuit board can be subsequently cut to separate discrete constructions from one another. The discrete constructions are referred to herein as integrated circuit packages. The smaller the individual circuit packages, the more likely it is for industry processing to utilize the above-described method of forming the packages on a single large board and subsequently cutting individual packages from the board.
An exemplary prior art process of separating integrated circuit packages is described with reference to FIG. 1. FIG. 1 illustrates a board assembly 10 having a plurality of IC chips 12 (only some of which are labeled) bonded thereto. Chips 12 are aligned into individual IC package configurations 14 (only some of which are labeled) to form a repeating pattern of integrated circuit packages 14 across the board assembly 10. Dashed lines 16 are shown to illustrate the boundaries between individual IC packages 14. In the shown exemplary embodiment, assembly 10 comprises three separate circuit boards 11, 13 and 15. The number and size of individual circuit boards can vary depending on the number and size of IC packages that are ultimately to be formed.
Each of boards 11, 13 and 15 comprises a pair of lateral waste sections 21, 23 and 25, respectively. The lateral waste sections 21, 23 and 25 are separated from the remainder of boards 11, 13 and 15, respectively, by imaginary dashed lines 20, 22 and 24. In further processing, the individual IC packages 14 are separated from one another by cutting through boards 11, 13 and 15 along the regions illustrated by dashed lines 16. During the cutting to separate IC packages 14 from one another, boards 11, 13 and 15 are also cut along regions illustrated by dashed lines 20, 22 and 24 to remove waste portions 21, 23 and 25 from the lateral sides of the boards, and accordingly from lateral edges of the ultimately formed IC packages.
Orifices 19 (only some of which are labeled) are provided throughout circuit boards 11, 13 and 15. Specifically, pairs of orifices 19 are provided in each IC package 14, and at least two orifices 19 are provided in each of waste portions 21, 23 and 25.
FIG. 1 further illustrates an IC package separator 40 comprising a cutting mechanism 42 (shown schematically as a cutting wheel, although other cutting mechanisms, such as, for example, router bits or linear blades, are known to persons of ordinary skill in the art), a retaining table 44, and a control mechanism 45 configured to control orientation of cutting wheel 42 relative to table 44. Retaining table 44 can comprise, for example, an x-y table (i.e., a table horizontally adjustable in x and y directions; an xe2x80x9cXxe2x80x9d, xe2x80x9cYxe2x80x9d and xe2x80x9cZxe2x80x9d axis system is illustrate in a lower corner of FIG. 1). Control mechanism 45 can control the x and y orientation of table 44 and the z (i.e., vertical) orientation of cutting mechanism 42 to precisely cut a board retained on table 44. Table 44, cutting mechanism 42, and control mechanism 45 can be comprised by commercially available cutting systems, such as, for example, Advanced Technology Incorporated""s CM101 single spindle router (or, more generally, a circuit board depanelization router).
FIG. 1 also illustrates that table 44 comprises an upper platform 46. A subplate 48 is provided over platform 46, and a stripper plate 50 is provided over subplate 48. Subplate 48 comprises a plurality of upwardly extending pins 60 (only some of which are labeled), and stripper plate 50 comprises a number of orifices 62 configured to slide over pins 60. Subplate 48 is retained on table 44 by downwardly extending pins (not shown) which are aligned with and precisely received within orifices (not shown) extending within platform 46 of table 44.
Orifices 19 of boards 11, 13 and 15 align with pins 60. In operation, boards 11, 13 and 15 are slid over pins 60 until the pins protrude through orifices 19. Typically, orifices 19 are only about 0.003 inches wider than pins 60 to insure tight alignment of boards 11, 13 and 15 with subplate 48. After boards 11, 13 and 15 are retained on table 44 by pins 60, cutting mechanism 42 is utilized to cut along the regions illustrated by dashed lines 16, 20, 22 and 24. Such cutting separates discrete integrated circuit packages 14 from one another, as well as from waste regions 21, 23 and 25. The separated circuit packages are retained on table 44 by pins 60 extending through the packages. Specifically, each of individual packages 14 comprises a pair of orifices 19 and is thereby retained on table 44 by a pair of pins 60.
After the IC packages are separated from one another, stripper plate 50 is manually lifted off of subplate 42 to lift the IC packages 14 from pins 60. Once stripper plate 50 is lifted off from pins 60, the individual IC packages can be separated from stripper plate 50. An exemplary method of removing the IC packages from stripper plate 50 is to tilt plate 50 and allow the packages to slide off plate 50. After the packages 14 are removed, plate 50 can be returned to over 48 and used again for separating IC packages.
Difficulties can occur in utilizing the assembly of FIG. 1 for separating IC packages. For instance, separated IC packages can be broken as stripper plate 50 is lifted from subplate 48. It would be desirable to reduce or eliminate such problems.
In one aspect, the invention encompasses a method of forming integrated circuit packages. A base having a plurality of pins extending upwardly therefrom is provided. A support is provided over the base. The support has an upper surface and a plurality of holes extending therethrough. The pins extend through the holes and upwardly beyond the upper surface of the support. An actuator is provided beneath the support. A board having a plurality of integrated circuits bonded thereto is provided. The integrated circuits form a repeating pattern of integrated circuit packages across the board, and the board has a plurality of holes extending through it. The board is placed over the support upper surface with the pins extending into the holes in the board. While the board is over the support upper surface, it is cut to separate the integrated circuit packages from one another. After the cutting, the support is vertically displaced by the actuator to lift the support off the pins.
In another aspect, the invention encompasses an integrated circuit package separator for separating integrated circuit packages from a board. The board comprises a plurality of integrated circuits bonded thereto, and has a plurality of holes extending within it. The separator includes a base having a plurality of pins extending upwardly therefrom and a support over the base. The support has an upper surface, a plurality of holes extending therethrough, and a pair of opposing ends. The pins extend through the holes in the support and upwardly beyond the upper surface of the support. The support and pins are configured such that the pins extend into the holes in the board when the board is placed over the support upper planar surface. The separator further includes a pair of actuators beneath the support and configured to vertically displace the support and lift the support off the pins. Additionally, the separator includes a cutting mechanism configured to cut the board while the board is over the support upper planar surface and thereby separate the integrated circuit packages from one another.